Project Summary Falls are the leading cause of injuries, hospital visits, nursing home admissions, and reduced quality of life for people with neurological disorders. Although there is consensus that impaired mobility is the basis for most falls, it is very di?cult to evaluate these complex abilities outside a laboratory setting. Brief clinical examinations do not accurately re?ect daily, functional mobility in real life environments. Patients at risk of falls would bene?t from a system they can easily use to measure their daily mobility, assess mobility ?uctuations throughout the day, evaluate their risk of falling, and measure e?ects of interventions aimed at improving their functional mobility and reducing their falls. No commercial technology yet exists to continuously monitor ?uctuations in mobility or quantify fall risk in natural environments during normal activities. We developed and validated an unobtrusive system, called Mobility Life, to objectively characterize gait and turning during spontaneous activities with wearable inertial sensors. During this Phase II, we will develop an instrumented ankle wrap for continuous monitoring of gait, develop a user interface to support clinical research, develop reports that show indications of fall risk for clinical practice, and thoroughly verify and validate our technology. We will also determine which metrics are most indicative of fall risk and determine normative values for non-fallers in the same age range as the expected patient populations. Our speci?c aims are: AIM I. Technology Development: Prepare Mobility Life for clinical practice. Milestone 1: Develop an instrumented elastic ankle bandage (SmartSox) for continuous gait monitoring. Milestone 2: Develop useful clinical reports to convey patients' daily mobility impairments, ?uctuations, and fall risk. Milestone 3: Complete the system veri?cation and validation in preparation for FDA 510(k) clearance to market. Aim II. Clinical Research: Demonstrate the clinical utility of Mobility Life to monitor quality of functional mobility and fall risk in neurological patients. Milestone 4: Determine which daily life mobility impairments best predict fall risk in patients with PD or MS. Milestone 5: Develop reference values for integrity of functional mobility in healthy age-matched subjects.